Imaging objects using polarized radiation is well known. Types of polarized radiation that are used for the imaging include linearly polarized and elliptically polarized radiation. Methods for producing other types of polarized radiation are known.
U.S. Patent Applications 2007/0159694 and 2005/0195480 to Brown et al., which are incorporated herein by reference, describe a system for converting homogeneously polarized radiation to inhomogeneously polarized radiation using a combination of isotropic and anisotropic media.
U.S. Patent Application 2007/0115551 to Spilman et al., which is incorporated herein by reference, describes a system for converting homogeneously polarized radiation to inhomogeneously polarized radiation using a spatially variant waveplate.
U.S. Patent Application 2006/0268265 to Chuang et al., which is incorporated herein by reference, describes a method for inspection of a sample. The method uses an illumination mode which “uses pure p-polarization, also called radial polarization because the electric field oscillates radially about the Z axis in a manner similar to spokes in a wheel.”
U.S. Patent Application 2006/0238865 to Biss et al., which is incorporated herein by reference, describes producing an inhomogeneously polarized optical beam from a homogeneous beam using two phase shifters and a polarization beam splitter. The disclosure also describes using the inhomogeneous beams for imaging.
U.S. Patent Application 2006/0007541 to Totzeck et al., which is incorporated herein by reference, describes an optical imaging inspection system. One arrangement of the system uses a radial polarizer.
An article titled “Inhomogeneous Polarization in Scanning Optical Microscopy” to Youngworth et al. Proceedings of SPIE Vol. 3919 (2000) is incorporated herein by reference. The article describes a scanning laser microscope using an azimuthally polarized beam.
Notwithstanding the present art, an improved imaging system using polarized radiation would be advantageous.